Coffee Consumption And The Risk Of Malignant Melanoma In The Norwegian Women And Cancer (NOWAC) Study

Marko LUKIC, Faculty of Health Sciences, University of Norway - The Arctic University of Norway, Norway

1 Department of Community Medicine, Faculty of Health Sciences, University of Tromsų, The Arctic University of Norway, Tromsų, Norway

​Background  Numerous biologically active substances contained in coffee have been found to suppress carcinogenesis. Some new evidence has suggested a protective effect of coffee intake on risk of malignant melanoma. Coffee consumption habits among Norwegian women allow us to study the impact of heavy coffee intake on melanoma incidence. 
Methods Information on total and filtered coffee consumption was available from self-administered questionnaires for 104 080 women at baseline in the Norwegian Women and Cancer Study. We also included update information on coffee consumption collected 6-8 years after the baseline data collection. Multiple imputation was performed as a method for dealing with missing data in the cohort. Multivariable Cox regression models were used to calculate hazard ratios (HR) for malignant melanoma.
Results During more than 1.7 million person-years, a total of 762 cases of malignant melanoma were identified. We found a statistically significant inverse association between low moderate (more than 1 and up to 3 cups/day)  and high moderate (more than 3 and up 5 cups/day) filtered coffee consumption and the melanoma risk compared to light consumers (≤1 cup/day) (HR=0.81; 95% CI 0.66-0.99, HR=0.77; 95% CI 0.61-.98, respectively; ptrend=0.02). We did not find any statistically significant association between overall coffee intake and the risk of malignant melanoma in any of the consumption categories (>5 cups/day vs ≤1 cup/day HR=0.88; 95% CI 0.67-1.14, ptrend=0.20).
Conclusion The data from the NOWAC study indicate that the moderate intake of filtered coffee could reduce the risk of malignant melanoma.